Many Mac users running a modern version of OS X El Capitan have noticed the Secure Erase Free Space feature has gone missing from Disk Utility. What the “Erase Free Space” feature did (and still does in prior versions of Mac OS X) was overwrite the free space on a drive to prevent file recovery, adding a layer of security and privacy to file removal, much in the way that Secure Empty Trash performed a similar function of overwriting data after removal.
For those wondering, these features were removed from the modern version of Disk Utility in Mac OS X because they do not work on SSD volumes, which are becoming more commonplace and nearly all Mac laptops ship with them by default now. But not everyone has an SSD drive, and thus some users may still wish to perform a secure erase of free space on their Mac hard disk. To achieve the same secure erase in modern versions of Mac OS X you’ll need to turn to the command line. And yes, this works to erase free space on older versions of Mac OS X too, but since they can do the same task with Disk Utility it’s perhaps a bit less relevant to the prior releases.
This is for advanced Mac users only who are comfortable with backing up their Mac, using the command line with exact syntax, and the concepts behind permanently removing data. To be perfectly clear, this secure erases only the free space on a drive, aimed at preventing file recovery efforts, it does not perform a secure erase of the entire hard drive as described here.
How to Secure Erase Free Space on Mac OS X El Capitan Drives via Command Line, Without Disk Utility
Back up your Mac before attempting to use these commands. The command line requires precise syntax and is unforgiving, improper commands could lead to the unintended removal of data you do not want to delete, permanently, as this is a secure erase function. You have been warned, so backup your Mac data first, then proceed at your own risk.
To get started, launch the Terminal (found in /Applications/Utilities/) and use the following general syntax, replacing level and drive name as appropriate:
diskutil secureErase freespace (level 0-4) /Volumes/(Drive Name)
(level 0-4) is a number indicating the number of passes to write to the free space, ‘freespace’ indicates you are erasing only the free space and not the entire drive itself – a critically important difference – and (Drive Name) is self explanatory. Users can also choose the disk identifier if desired. If you aren’t sure of the name of the drive, using diskutil list will show you all mounted drives and partitions. If the drive in question has a space in the name, you should place it in quotes or escape it with backslashes.
For example, to perform a secure erase with 35 passes on free space on a drive named “Macintosh HD” you could use the following command string:
diskutil secureErase freespace 3 "/Volumes/Macintosh HD"
Hitting return will instantly begin the secure erase of any free space. This is irreversible, so as we’ve mentioned a dozen times already, be sure the syntax is exact.
The manual page entry on diskutil offers the following details on the secure erase feature, detailing the level of writing over free space.
That’s all there is to it, and this is how you can continue to erase free disk space on a Mac running OS X El Capitan or later with the newly limited Disk Utility. Another option is to use an old version of Disk Utility in modern versions of Mac OS X, either from a boot drive or recovery mode, of an older Mac OS release, or with the application itself, but that is generally not recommended.
And yes, this works on both standard hard disk drives with spinning platters, and modern SSD disks, though with an SSD drive the feature is less relevant as TRIM / garbage collection should handle the file removal on it’s own. For SSD volumes, a better option is to enable and use FileVault disk encryption on the Mac, which encrypts data on the drive making it unrecoverable without the FileVault key, thus obviating the need to securely erase free space on the volume.
Know of any other helpful secure data removal tips or tricks, or another way to securely erase your free disk space in modern versions of Mac OS X? Let us know in the comments.
Evidence that Apple will rebrand OS X to MacOS is starting to pile up, with the new name appearing briefly on Apple’s own website.
As spotted by 9to5Mac, Apple’s Environment page got an update on Thursday, and for a short time it included a reference to MacOS. “Years of use, which are based on first owners, are assumed to be four years for MacOS and tvOS devices and three years for iOS and watchOS devices,” the page said. (Apple has since reverted the name to OS X.)
This isn’t the first time the potential name change has slipped out. Last month, an Interface Builder document inside the OS X system folder included a file named “FUFlightViewController_macOS.nib” (emphasis ours). Still, 9to5Mac noted that the name could have been included for the sake of convenience, as developers sometimes prefer the symmetry of iOS and macOS suffixes together. The name’s appearance on an official webpage seems like strong evidence.
Also worth noting: Last June, Apple marketing head Phil Schiller vaguely hinted at more name changes to come, after the company announced “watchOS” for the Apple Watch. “I think, you’ll see. Give us time, we’ve been through many fun naming things,” Schiller told John Gruber during a live podcast at Apple’s WWDC conference. (At the time, however, Apple still hadn’t revealed “tvOS” for the Apple TV.)
Why this matters: A name change would make sense given that all of Apple’s other operating systems now fall under the [prefix]OS naming scheme. And given that Apple has been updating the desktop version of OS X for more than 15 years now, the roman numeral for 10 has long outlived its functional purpose. MacOS—or, perhaps, macOS—could be a fun throwback to the operating system’s origins, while positioning it for the future alongside Apple’s broadening range of phones, tablets, watches, and TV devices.
If you’re troubleshooting a Mac machine with some particularly odd issues that routine measures don’t seem to be resolving, it can be helpful to list what kernel extensions are activated, particularly third party kexts loaded in OS X.
Determining what kernel extensions are loaded and running in OS X is rather easy, and using grep you can then easily list all third party kexts. You can also use the same command to list native kernel extensions as well. To accomplish this, you’ll use the kextstat command and pipe the output to grep, using the command line. This works the same in all versions of Mac OS X.
How to See All Third Party Kernel Extensions in Mac OS X
The full syntax to see third party kernel extensions is as follows:
kextstat | grep -v com.apple
The output is going to vary depending on what, if any, third party extensions are in the kernel. It may look something like this:
Index Refs Address Size Wired Name (Version) Linked Against
117 0 0xffdddfff8209ff910 0x2000 0x2000 com.radiosilenceapp.nke.PrivateEye (1) 4 1
119 0 0xfffff945818248770 0x3000 0x3000 com.whattheheckisthis.WeirdExtension (1) 5 2
If you see something out of place in that list, that could be a good place to start troubleshooting.
How to List All Kernel Extensions in OS X
Of course you can always list all kernel extensions (meaning, Apple’s official Mac OS X kexts included) by just typing the following command string:
The output here is going to be significant, but it can still be valuable.
If you want to learn more about kextstat, just type ‘man kextstat’ to open the man page in the OS X Terminal.
Don’t forget that you can manually inspect the traditional kernel extension system folder location as well if necessary, even moving and removing kext files from there to aid in the process of installing, uninstalling, troubleshooting, or discovery of kernel extensions.
Many Mac users will download package files of combo updates or other software in order to install them on multiple computers, thereby avoiding updating with the Mac App Store. This is particularly common with Mac systems administrators, where it makes more sense to download a single package update or installer once and distribute it over a network or perhaps install manually through a USB drive. There is nothing wrong with this approach at all, and in fact it’s much more efficient for multi-Mac management, but one potential hiccup arrives when a package installer or update file has an expired certificate, which will prevent the package from installing entirely, a situation that becomes obvious when you get an “(application installer) was signed with a certificate that has expired” error message.
To avoid this situation, you can check package signatures yourself to see if they are valid, if they have expired, or even if they have no signature at all.
How to Check Package Signature Status in Mac OS X with pkgutil
The excellent pkgutil command line utility can easily determine the status of any package signature and certificate. It’s easy to use, so launch the Terminal app from /Applications/Utilities/ and try it out yourself.
The basic syntax to use for checking a package signature status is like so:
pkgutil --check-signature /Path/to/Example.pkg
Hit return and you’ll find out if the signature is valid, if the signature has expired, or if there is no signature at all.
For example, let’s say we have an Mac OS X Combo Update software installer package, a common scenario for sysadmins updating multiple Macs, you could check the status of that packages signature like so:
pkgutil --check-signature ~/Downloads/OSXUpdateCombo10.10.2.pkg
Status: signed by a certificate that has since expired
In this case, the signature for the update package has expired, meaning it will throw an error if usage is attempted.
Not all package installers have signatures however, and while any software update file from Apple will, packages from third parties often do not. For example, this example package installer file has no signature, and should be treated appropriately (i.e. if you don’t trust the source, perhaps reconsider using it).
pkgutil --check-signature ~/Downloads/MysterySketchyInstaller-21.pkg
Status: no signature
If a package file is dubious, you can verify the code signature and extract the package without installing it with pkgutil to give it a further inspection, or if you prefer to use the GUI then an app like Pacifist offers similar package management tools in a friendlier interface, even if it’s still on the advanced side of things.
Like all good command line tools, you can even feed pkgutil wildcards to easily check multiple packages at the same time, in this example we’ll check the signature of every *.pkg file contained within ~/Downloads:
pkgutil --check-signature ~/Downloads/*.pkg
Status: no signature
Status: no signature
Status: signed by a certificate that has since expired
Wildcards will make quick work of checking certificate status of many different package files, just be sure you specify *.pkg for the process to complete without stopping on a file that is not a recognized package.
Creating animated GIFs out of a movie file or or video usually requires a bit of effort, but now you can convert a movie into an animated GIF on a Mac with drag and drop simplicity, thanks to the aptly named Drop to GIF.
Drop to GIF is a free app for Mac OS X which automates the entire animated GIF creation process, all you need to do is toss a movie file into the app and the conversion begins. The app is both extremely simple and effective, so if you’re looking to make quick work of gif creation using existing movie or video files, it’s an excellent choice to get started.
Making Animated GIFs with Drop to GIF in Mac OS X
Here is how simple the movie conversion process to GIF is:
Get Drop to GIF from Github (free) and launch the app
Drag and drop any movie file into the Drop to GIF app, or the app Dock icon, to start converting the chosen video to animated GIF
When conversion is finished, look in the original directory of the movie file to find the exported animated GIF
The exported GIF will loop endlessly, and the default settings will pull the frame rate from the video and set that as the animated GIF FPS as well. Users can make changes to FPS, width size of the animated GIF output file, and GIF quality, adjusting these three settings helps to control the file size of the exported GIF, since a large high FPS animated GIF will wind up being a large file by default. To access the settings, just click on the little gear icon in the app.
There’s even a little handy directory watching feature, where any movie file that appears in a watched directory will instantly be converted into an animated gif. As already mentioned, any exported animated GIF file will be saved in the same directory as the originating movie was, so that directory would contain both the origin movie file and the GIF output.
Here are a few example movies that were converted using Drop to GIF, this one is a quick capture from an iPhone movie that has been compressed heavily:
In this example, the original video is a simple screen recording .mov file made from QuickTime and there has been no compression or quality reduction, meaning the file is a bit on the large size:
For users who need more gif creation and movie conversion options, like a timeline and editing tools, a paid app like Gif Brewery for Mac allows you to convert video to GIF and make edits as well, which would perhaps be a better option for more avid GIF makers. But even if it has fewer features, Drop to GIF is an excellent app, and since it’s free there is little commitment to giving it a try and seeing if it works for your needs.
(By the way, if the Github page looks familiar to anyone, it’s because Drop to GIF arrives from the same developer who brought us the excellent simple language text editor ClearText, which is another fun little app for Mac users.)
We’ve all noticed Apple’s latest operating system nomenclature, with each new release a device-centric OS, like iOS, tvOS, or watchOS
Why not macOS, then?
A bit of source code in the current stable release of OS X (10.11.4) seems to point to that very thing.
Developer Guilherme Rambo told Portuguese-language site MacMagazine.com.br that he found an interface file (FUFlightViewController_macOS.nib, in the FlightUtilities framework) that uses the macOS terminology in the file name.
Surely Apple is looking to this as a possible renaming of OS X, which would fit it right in with it’s OS naming for its mobile devices, Apple TV and Apple Watch. It would make sense to launch MacOS 11 this year, too, with new OS versions across the line up (iOS 10, watchOS 3 and tvOS 10) to make it a banner year.
The UNIX-based OS X has been around for 15 years, so it’s probably time to start calling it something new. Originally named after big cats (Puma, Cheetah, Jaguar, Panther, Snow Leopard, and so on), recently the team at Apple has named the different releases after places in California, like El Capitan and Yosemite. There’s no reason Apple can’t continue this naming convention; it’s just that making the OS match the device name would make things a bit clearer to customers.
While we don’t really know what the plan is, we do hope to see the arrival of Siri on macOS (or whatever it’s called in the next release). It would make a lot of branding sense, for sure. Here’s hoping.
The OS X El Capitan 10.11.4 update improves the stability, compatibility, and security of your Mac, and is recommended for all OS X El Capitan users.
Adds the ability to passcode-protect notes containing personal data in Notes
Adds the ability to sort notes alphabetically, by date created, or date modified in Notes
Adds the ability to import Evernote files into Notes
Adds support for sharing Live Photos between iOS and OS X via AirDrop and Messages
Addresses an issue that may cause RAW images to open slowly in Photos
Adds the ability for iBooks to store PDFs in iCloud, making them available across all your devices
Fixes an issue that prevented loading Twitter t.co links in Safari
Fixes an issue that prevented the VIPs mailbox from working with Gmail accounts
Fixes an issue that caused USB audio devices to disconnect
Improves the compatibility and reliability of Apple USB-C Multiport Adapters